Mcsigajl instrument



June 7, 1949. u z 2,472,595

MUSICAL INSTRUMENT 4 Sheets-Sheet 1 Filed Jan. 15, 1946 11H t I Ill 0INVENTOR. J74co5 7.'/ u/vz June 7, 1949. J. T. KUNZ MUSICAL INSTRUMENT 4Sheets-Sheet 2 Filed Jan. 15, 1946 m V u K "r I O T .m T M A 3 June 7,1949. 7 J. T. KUNZ 2,472,595

' MUSICAL INSTRUMENT Filed Jan. 15, l946 4 Shee'ts-Sheet 3 I g '75 I V r'9 9.

mmvroz; JACOB 7. u /vz BY 34" 44M s /LW June 7, 1949. J. 'r. KUNZMUSICAL INSTRUMENT 4 Sheets- Shet 4 Filed Jan. 15, 1946 m T w W.

4 TTOQNEYS Patented June 7, 1949 Jacob. T. Kunz,.

North Hills, Pa., assignor to Schulmerich Electronics,

Incorporated, Sellersville, Pa... a corporation of PennsylvaniaApplication lanuary 15, 1946,. Serial No. 641,242;

10. Claims. 1

Thisinvention. relates to: a.- musical instrumentand particularly toone; having aplurality of vibrators which may besetinmotion to producemusical. tonesv such: as: an: instrument: commonly referred to. as anelectric. carillon. In such an. instrument, the vibrations oftuned=.rods:;are.- am.- plified electrically to faithfully reproduce.the tones of bells or chimes.

One of the. many advantages of an electric carillon over conventionalcast bells-is. the: large. saving in weight which eliminates .the:necessity of special structural provisions for housing the carillon. Forexample; whena carillon of twentyfive bells or notes is used, the weightof an electric carillon made in accordance with the present inventionWill be about 200' pounds: as. compared with a weight of possibly 50,000pounds for conventional cast metal bells.

Other advantages are that the electric carillon is not affected bytemperature changes-and that the volume and. sound radiation patterncan,

be controlled with case. In addition, a console or keyboard similar toan organ or piano can be furnished so that no special'skill is requiredin playing.

One of the objects of. the present invention. is. to provide aninstrument having. rodstuned. in such a. manner as to produce bell.orchime tones.- correctly and without distortion.v previous devices, therelationship between the fundamental note andthe harmonic pattern-oi":the various: rods varied with each rod so that the instruments. did notproduce the music of perfect bells, The rods contemplated. herein are.each tuned. to a certain predetermined; tone .andsthen. means. providedfor giving: an even. harmonic pattern for each of said. rods.

It has been found that a good is one in which the hum tone, thefundamental: tone, a minor third,. a fifth, and an octave.abovethefundamental appear. The fundamental-tone of. the bell is themost prominent tone at the instant of striking and is taken as the basisfrom which the other tones are measured, it beingnoted that thefundamental tone in a bell is not the lowest frequency present. The tonean octave or other interval below the fundamental is called the hum noteor hum tone. The "minor' third and the fifth are between thefundamental.and the octave above the fundamental. A bell tone can be generated by arod or similar element clamped at one end by tuning the same to thethird tone, treating the third tone as the fundamental with the secondtone as the hum tone, and bringing the other desiredv partials and tonesinto correct. relationship. The first tone of the rod is not useddirectly but is filtered, outv of the amplified sound in the electriccircuits by means of suitable frequency filtering means. One of theresults is the elimination of the objectionable. clang sometimes heardin. bells and particularly in electrical bell tone reproducing, means.

The frequency characteristics, of a rod clamped, at, one. end does notgive the desiredeven harmonic pattern which has; just been. mentioned.and one object of the present invention to provide means to cause therod to produce the desired even harmonic pattern. The specific method.of tuning is described and claimed in copending applicationSerial No.672,820, filed May 28, 1946.

In. an instrument for translating musical vibrations of a. rodtoelectrical. vibrations,v amplifying. the vibrations, and then changingthe electrical vibrationsto. sound vibrations with. high amplification,it is necessary to. carefully arrange and select all of the mechanical.andelectrical. elementsin order toproduce. the desiredv tones withoutdistortion. When electric. carillon bel-l notes are to be reproduced ina sound system, the rod must be properly tuned. and the striker meansarranged to give the desired and correct vibratory motion of the rod.

Another of the objects of the present invention is to provide a strikerwhich can be ad,- justed with ease to give the correct blow to a rod,this being important inasmuch as the slightestv difference in the blowcan be detected easily by the trained ear. The striker preferably is ofthe pivoted and: freely swingable pendulum type held normally in anenergized position or so that it is angularly located relative to avertical line through the striker support. Uponrelease oi a restrainingmeans for a striker, the selected striker will freely swing and'give itsassociated rod a blow.

Another object of the invention is to provide a restrainingand releasingmeans for the strikers which can be selectively operated to allow thedesired striker or strikers to freely swing and impart vibrations: tothe selected. rods, and at. the same time not to interfere in any withthe freely swinging movement of a, released striker and thereby possiblychange the force with which thestriker hits a rod. The striker and.restraining means are the subject matter of and are claimed inco-pending application, Serial Nor 641,243, filed January 15, 1946, nowPatent No. 2,463,543., issued. March 8, i949.

Another object of the invention is to provide an electrical pick-up orcollector plate arrangement which can be adjusted easily to give thedesired volume and tone for its associated rod. The collector plate fora rod is divided into a plurality of individually adjustable elements,such an arrangement providing for easy adjust ment, allowing any numberof plates for a rod to be used, and making possible adjustments tocompensate for irregularities in the homogeneity or shape of aparticular rod.

The clamping means for each rod is arranged to provide a positive gripor solid clamp at the point where the rod leaves the collet, said gripbeing adjustable so as to give the desired tones for a particular rod.For example, a tight grip will allow a note to be generated in a rodwith high overtones, the high overtones being easily clamped by apartial contact of a clamp with the rod caused by a poor grip.

These and other objects of the invention will become apparent from thefollowing description and drawings which are merely exemplary.

In the drawings:

Fig. l is a perspective View showing the front and one side of the rodand striker frame assembly or mechanism.

Fig. 2 is a broken perspective vertical front view of the rods andsupporting bar.

Fig. 3 is a fragmentary plan View of the striker assembly taken alongthe line 3--3 of Fig. 4.

Fig. 4 is a cross-sectional View taken along the line 45 of Fig. 3, theright-hand rod being shown in full lines. I

Fig.5 is an enlarged fragmentary vertical section along the line 5-5 ofFig. 4 showing details of a striker pivot.

Fig. 6 is an enlarged sectional View showing the mounting for one of thecollector plates.

Fig. 7 is a fragmentary plan view of some of the magnets and a portionof the carrier, the View being taken approximately along the line 7-1,the magnets being shown in full.

Fig. 8 is an enlarged detail view partially in section of a collet witha portion of a rod therein.

Fig. 9 is a schematic showing of one of the circuit arrangements thatcan be used.

In the preferred form of the invention described herein, an instrumenthaving twenty-five notesor two octaves is employed, but it is to beunderstood that an instrument with any numberof rods may be used.

In the schematic showing in Fig. 9, striker 2B normally is held in anenergized position by magnet 2!, said magnet normally being energized bya source of power 22 through normally closed switch 23, said switchbeing opened when a key of the console or keyboard is depressed. Rod orvibrator 24 is carried in heavy rod support 25. Condenser or collectorplates 26 are mounted on collector plate support bar 34, said platesbeing connected by wire I 00 with a pre-amplifier AA, rod 24 beingconnected to the ground through support 25. Pre-amplifier A-A in turn isconnected by wire I08 with amplifier B-B, said amplifier B-B beingconnected to loudspeaker I28. The pro-amplifier is mounted adjacent tothe rod and striker mechanism assembly as indicated at 82 in Fig. 1 soas to amplify the vibrations for proper transmission to an amplifierlocated at some point between the rod and striker mechanism and theloudspeaker I28. Inductance 32, resistance 98, and the capacitance ofthe relatively long leads 99 will suppress any disturbance in thestriker release mechanism which might affect the amplifier circuit,resistance 98 being shunted across the magnet to reduce the reactance ofthe circuit to the radio frequencies generated by an opening of switch23. The switch suppressing elements can be mounted on the frame as seengenerally at 8| in Fig. 1, It is to be understood, of course, thatvarious combinations and arrangements of the amplifier circuits andloudspeaker may be used.

When switch 23 is opened, magnet 2i will release striker 20 allowing thestriker to swing on its pivot 27 and strike rod 24, the vibrations ofrod 24 causing a variation in the electrical capacity between thecollector plate 25 and rod 24, plate 26 and rod 24 being given apolarizing or operating potential in a manner hereafter described.

As explained previously, in tuning the various rods of the carillon, itis desirable to obtain the tone appearing in a good bell, namely, a humtone, a fundamental, a minor third, a fifth, and an octave. When a rodor bar is clamped rigidly at one end and with an unsupported free end,there will be certain predetermined frequency ratios between theovertones and the fundamental, these ratios having been established byphysicists such as Rayleigh in Theory of Sound. As indicated in Table I,the frequency ratios of the first 4 tones being given, these ratios in arod clamped at one end not being even multiples of the fundamental.

Table I Fre. Freq of D Resultant esired Fre- Tone (3 as of Tone fig ggfgg quency Fundamentel) 1 (Basic).. f 10 1+2- 72 2 6. 26f 62 87.5 (HumTone) or 3 55! 175 (Fund) 3-175 Minor Third. 2-1-3-237 ifth 2+3+22993434f 343 350 4-343 Assuming that the first or basic tone has afrequency of 10, the frequency of the second, third, and fourth toneswill be 62, 175, and 343, respectively. If the third tone be taken asthe fundamental, it will be noticed that the fourth tone is slightlyunder the octave above or twice the frequency of the fundamental. Thesecond or hum tone, is not /2 of the frequency of the fundamental. Thedesired frequency of the various partials with the third tone as thefundamental including the minor third and fifth is indicated in thefourth column of the table. The hum tone is produced as a result of thecombination of tone 3 minus tone 2 or 113 vibrations per second, thisbeing accomplished through the phenomenon of beats as is well known. Theminor third is arrived at by a combination or beat note between tonestwo and three and the fifth is a combination between the minor third andthe hum tone. The resultant tones are not as close as is desired to thetones set forth in the desired frequency column.

It has been ascertained that the tones are brought closer to an evenharmonic pattern by cutting a groove or grooves 8t (Figs. 4 and 8) nearthe point where the rod is clamped in the collet and exteriorly thereof.There may be more or less grooves than the number shown. The exactreason for this phenomenon is not precisely known although it may havesome analogy in the fact "that when circuits or vibrating members aremade unstable or are given the opportunity to vibrate with evenharmonics they will sodo.

By grooving the rod' 35 neartheclamped end, opportunity is given for the'rodto vibrate in an even harmonic pattern. The base frequency isdetermined by the strongest tone present in the rod or which is beingpicked off the rod, this being 175 cycles per second in-the example ofTable I. Grooving of the rod permits tone 4 to vibrate substantially at350 cycles instead. of 343 and also permits the rod to vibrate Orproduce a hum tone of 87.5 cycles per second instead of .62 or 113cycles per second. l hus the grooving causes the relationship betweenthe fundamental shoulder T6 is located atone end of the collet-with a"greater diameter "than the-reduced portion 11 thereof,aperture!8-having-a=tapered wall 19ccoperable withthe tapered shoulder160i the collet. When :themuts are tightened with the collet in placeanda-rod is in socket 15, the tapered'shoulder 16 will cooperate with thetapered socket J9 to-causethe spring fingers to-grip the rod tightlyatthe point where the rod emerges from=the-collet. In this way, thetightness with which the *rod is gripped can be adjusted by meansof-nuts-M. The tighter the rod is gripped, the-less thedamping of thehigh overtones. -A loosening of thegrip on the rod will result in thehigher overtones being damped more quickly.

tone and theoctave to fall into an even relation- Such a constructionassures that the gripping ship. action positively takes place at theouter end of Actual tests have shown that the partials in the collet sothat a positive grip will be made an unnotched rod can be off as much as.30 or 40 at the point where the rod leaves the collet. A cents in-arod, a cent being defined as an intertight grip will thus permit. thehigh overtones to val between any two tones whose frequency ratiodevelop and permit them to travel up the rod is the twelve hundredthroot of two, whereas the whereas with a loose grip, the vibrations willbe rods can be tuned to show a deviation of only absorbed by the colletfingers. 5 or 6 cents by grooving. When a deviation of As previouslymentioned, the metallic base is about 12 cents is present, dissonanceusually berelatively massive as compared to the rods so as comesnoticeable between the rods and tones in to keep the base from enteringinto the generated the rods vibrations of the .rods. Base 36 has crossbars In addition to thelgrooving of the rod, a weight 3'! at either endthereof, .said cross bars being in the form of a ring around the rodwill help carried by means. of resilient Sup 38. The in the case of thehum tone and fundamental, resilient 1 9 33 y be o t e rubber-insaid ringpreferably being placed near a tonal s ea type such as'sold'on themarket under the node. The weight will shorten or lengthen, as name Lord.Bonded Rubber Mounting or a the case may be, the frequency of thevibration similar support. of the particular section. A similar effectcan be Mounted on base 35 by ins l 111 4| secured by notching the rod inthe correct place 1 is eco lector plate suppo bar d '0 but the slidingrings are preferable because they l cter plate bar -40 carryin WO Su t nially may be more easily adjusted and placed on the fiat 0011601101'p1ates'42and 43 for each red, but it -is to be understood that anynumber of col- As an example of the tuning of the lowest and p -mye'employed for'each'rod. The highest pitch rods of one form oftwenty-five 40 Plates are fid 011 13BX40 3-a d'Fig. 6) note or 2 octaveelectric carillon reference is y means of a Screwthreade'd stud 45 whichis made to Table II. spaced from bar 40 by means of sleeve 46, the

Table II Low 1G196- High G784- Name of Tone gg d fiigg Resultant TonesPag Resultant Tones 1(Basic1one). f 11.1 44.6 Z'Hum Tone--- 6. 26f 9869.5 80. 5 392 270.5 324.1 1+2 1+2 s-Fund 17. ssr 196 196 19g 784 78478% Third (Minor) 251 265. 5 1045 1063 2+3 2+3 4 Octave 34.3% 392 331.7381.1 1568 1540 1540 Rods or vibrators 35 can be formed from brass orother suitable metal and should be as symmetrical and homogeneous aspossible, circular rods beingshown herein. Rods 35 are held in the heavymetallic base 36 or rod support by meansof suitable collets or clamps.39. The metallic base 35. should be relatively massive as compared 'tothe reeds and should have a high modulus of elasticity such as possessedby steel.

A collet or clamp 39 (Fig. 4 andFig. 8) may be composed of a singlepiece of metal aving a screw threaded extension 13 and four springfingers. A socket 15 is provided in the collet for holding one end ofthe rod 35. A tapered upper plate 42 being shown in Fig. 6, the otherplates being supported in a similar fashion. The other end of thecollector plate/42 has a straight wall aperture '41 with a conical headscrew 48 therethrough. By turning screw 48, the distance between thecollector plate and its rod may be varied. Rods'35 may have aninsulating or fungicide coating, such as shown at '45, placed thereon ifdesired, although-such is not required.

By the use of a plurality of collector plates, it is easier toalign theplates along longitudinal portion of the rod than it is "to align asingle plate extending over the same distance and this is --particularltrue whenithe ro'd sis not za'bsolutely symmetrical. As an example, itis easier to obtain a, high capacity between four 4 plates over a 1"section of rod than it is to obtain the same capacity with one 1" plateover a 1" section or rod. In addition thereto, the multiple collectorplate arrangement enables the manufacturer to leave some of the segmentsof the collector plate assembly blank so that they can be connectedthereafter in case it is so desired. A muitiplate collector also enablesVernier adjustments of volume. The collectors preferably are mountednear the gripped end of the rod so that when the rod is struck, a toneis produced that is full and rich in harmonics.

The striker assembly carrier can be constructed of two flanged platesll; having upper and lower cross bars d and El joining each end thereofand attached to the flanges by means of bolts M. A rubber-in-shear orsimilar support 52 is carried by bar 53 mounted by means of bolts 5:? tothe heavy metallic base 36. Lower carrier cross bars ti may haveapertures ll therein to allow access to adjusting bolts 3b of theresilient mounts 52. The striker assembly carrier thus is resilientlysupported on base 38 thereby minimizing or eliminating vibrations set upin the carrier from being transmitted to the rods, this being especiallyof value when the magnets are operated by alternating current. Base 36,in turn, is resiliently supported on the main frame 55 of the rodassembly. The main frame 55 can be mounted on brackets 55 which areconnected to structural members of the building or any suitablesupporting means.

Striker hammers 51 may be of any suitable material and adjustably heldby means of nuts 58 on shanks 59 of the striker, shanks 58 preferablybeing made of a magnetic material and freely swingable and supported onpivots El. The preferred form of pivot comprises two conical pointscrews iii (Fig. 5) which are held in bifurcated arms '53 of frames 62.Frames 62 have spring clamps 53 mounted thereon by means of screws $4 sothat the conical point pivot screws 5! can be adjustably held on saidframes. Shank 59 has mating conical depressions 65 (Fig. 5) co-operatingwith the conical pointed screws.

The pivot friction can be adjusted to the desired degree and springclamps 63 will serve to hold the pivots in said adjusted position. Vari-0115 other equivalent arrangements of the pivot assembly, of course, maybe employed.

Frames 82 permanently are fastened by means of screws 65 to the strikerassembly carrier flanges til. The upper end of each frame 62 abuts anadjusting screw 6?, said adjusting screw having a lock nut 58 thereon.The position of the striker pivot relative to a rod and the pivot pointsreadily may be adjusted so that the swing of a striker will be correctand have the proper intensity or striking velocity.

Electromagnet 69 can be mounted on frames b2, said magnets normallybeing energized so that shanks as will be held against stop elements #2.Upon release of a magnet, the pendent freely swingable striker willswing from the position indicated in broken lines in Fig. 4 and hit rodElli setting the same into vibration. The energy used striking the rodis sufiicient to reduce the return period of the striker so that thestriker will hit the rod and bounce clear.

A resilient adjustable stop element 12 is carried by screws ill and locknuts H, stop elements 12 preferably being of a material which providessome cushioning action but is sufiiciently hard so that it does notpermit the shank to bounce when it hits the top. One of the materialsthat may be used is a linen base Bakelite, but there are, of course,other similar suitable materials. The arrangement is such that thestriker will strike the rod only once when the key is depressed, themagnet again holding the striker in an energized position when the keyis released. A semi-resilient stop also will serve to absorb anyvibratory motion of the shank due to the alternating current of themechanism as explained in detail in the aforementioned co-pendingapplication, Serial No. 641,243.

The magnet coils have their polarity or windings arranged so that pairsof adjacent magnets have opposite polarity as indicated by the plus andminus signs in Fig. 7. For example, when magnet d is de-energized torelease its associated striker, the magnetic fields on either sidethereof caused by magnet c and 6 will be equal and opposite and willneutralize each other as far as the striker d is concerned. The magnetsare operated at an extremely low density so that the inertia of thestriker provides much the same effect physically that a shading poledoes electrically in an A. C. magnet operated at relatively highdensity.

in one form of an electric circuit that may be used, collector plates 2tare connected through lead Hill with the pre-amplifier circuit shown inbox A-A of Fig. 9, control grid ll of the preamplifier tube it: beingconnected through condenser mil to wire 10.

The plate circuit of tube I02 includes a connection to plate powersource Hi3, plate [04, cathode W5, and cathode follower I06. Thepolarizing or operating potential for the reed d c Elector plates isobtained from power source resistance ltd, and resistance I31, thesignal being generated across resistance i3l. Power source it can betied (not shown) in some suitable manner with supply line H9. The signalacross the cathode follower I05 is taken through condenser it! andconnecting lead I08 to the amplifier circuit shown in box BB. Normallythe lead 508 is of considerable length to allow placing of the amplifierwhere desired.

The filament or heater element of tube N12 is supplied from a suitablesource through connection I09 and a husrnbucking network is provided atl i I. The network is connected to heater leads I09 and through wire H0feeds an alternating current voltage similar in magnitude and out ofphase with the heater voltage to the carrier frame 29. When alternatingcurrent is used to energize the magnet coil 2|, 2. fiux is generatedthereby and the collector plate 26 and bar 34 are in said flux so thatan alternating current iof line frequency may be induced in thecollector place circuit. By introduction of the out of phase voltagefrom network HI into carrier 29 the undesirable induced voltage due tothe magnet coils is neutralized. The network may have an adjustableground on one resistance and a center tap resistance in parallel so thatthe desired voltage and phase relationships are obtained.

Amplifier B--B is one of conventional type having its circuits. arrangedin combination with the other circuits to attenuate the low frequency asexplained hereafter. vWire I08 is connected to the control grid H3 ofamplifier tube H4. The signal from the plate circuit of tube H4 iscarried to grid N6 of the duplex triode mixer tube l-I--I throughcondenser I04. Tube III may be of the type designated as BSN'I, but itis, of course, possible to use a single triode or other type of tube;Wire H8 may be connected to power lead H9 to supply plate voltage to themixer tube I11 and amplifier tube I25.

For the particular'pitch scale of the carillon chosen, the circuitsassociated in amplifier B-B with condensers I04 and H2 are arranged sothat the low frequency response of the amplification system will beattenuated approximately 8 to decibels 'at a-frequency of 100 cycles persecend. As explained previously, this serves to attenuate low frequencyin the amplifier circuit so as to make the first tone of the vibratingrod inaudible through the system. It is to be understood that condensers!!33 and'IU'I together with their associated circuits might also serveto attenuate undesirable frequencies depending upon the pitchrange ofthe instrument. In addition, the bass may be cut to the extent of 15 todecibels through the attenuated low frequency response of a suitablyselected horn or loudspeaker I28.

Merely as an example for one type of instrument, condensers I03, I01,I04, and H2 may have capacities of .01 f 1 ,uf., .005 .f., respectively.Resistances. I32, I33, I34, and I35 may have values of 10 megohms,10.0.0 ohms, 500,000 ohms, and 500,000 ohms, respectively.

A microphone and amplifier combination C-C may be provided and connectedto grid l2l of mixer tube H1 and a phonograph D-D may be connectedthrough wire I22 to the plate circuit of tube III. The signal from theplate circuit and phonograph, if used, is taken from point I23 throughcondensers H2 and the bass control network I24 to amplifier tube I25.The plate circuit of amplifier tube I25 is connected by means of wireI26 to the loudspeaker or to other amplifiers if necessary, a treblecontrol I29 being provided if desired. Amplifier tubes I02, H4, and I25may be pentodes of the type designated as 6SJ'7. Tubes I02 and I25 havethe screen and supressor grids connected together to the plate thereofso that the tubes operate as triodes.

It is to be understood, of course, that the microphone and phonographmay be omitted and that various types of tubes and high grade amplifierscan be used, the circuits shown being only one example of a suitableamplification system. The amplifier should have the attenuationcharacteristics mentioned above and should be of the low distortiontype.

Various modifications may be made in the described device Withoutdeparting from the spirit of the invention or the scope of the appendedclaims.

I claim:

1. In an electric musical instrument, a, plurality of rods, each of saidrods being tuned to the third tone thereof and each rod having meansthereon to produce an even harmonic pattern relative to said third tone;normally restrained pendent freely swingable strikers selectivelyreleasable for striking rods; an electrical pick-up for each of saidrods; an electric circuit connected to said pick-ups attentuating thefirst tone of each of said rods; and a loudspeaker connected to saidcircuit to produce tones when said rods are struck having substantiallythe same relationship between the fundamental tone of a rod and theharmonic pattern therof for all of said rods, said third tone serving asthe characteristic tone and the second tone as the hum tone.

2. In "an electricrnusical instrument a plurality of'fixed-free rods,each of saidrods being tuned to the third tone thereof and each rodhaving aneven harmonic pattern producing means -'thereon; selectivelyoperable strikers for said rods; an electrical pick-up for said rods; anelectric circuit connected to said pick-up, said circuit attenuatingbetween about a minimum of 8-10'decibels the first tone of said rods;and a loudspeaker connected to said circuit, said loudspeakerattenuating the bass of said circuit between about a minimum of 15-20decibels and producing tones when said rods are struck havingsubstantially the same relationship between the fundamental tone of arod and the harmonic pattern thereof for all of said rods.

3. In an electric musical instrument, a plurality offixed-free rods,each of said rods being tuned to a predetermined tone and having groovescut therein adjacent the fixed end thereof to produce an even harmonicpattern; selectively operable strikers forsaid rods; translating meansfor changing mechanical vibrations of said rods to electricalvibrations; arr-electric circuit attenuating predetermined tones of saidrods; and an electro-acoustic means fortranslating said electricvibrations into tones when said rods are struck having substantially thesame relationship between the fundamental tone of a rod and the harmonicpattern thereof for all of said rods, said electro-acoustic means havingmeans to attenuate the bass.

4. In' an electric musical instrument, a relatively'heavy resilientlymounted base; a plurality of tuned rods carried on said base; a pivotedfreely swingable pendent striker for each of said rods; an electromagnetfor releasably holding each of said strikers in an energized position;means to selectively release said strikers; a resiliently mountedcarrier; an adjustable electromagnet andstriker support frame for eachof said strikers mounted on said carrier; a multiplate collector withclosely adjacent platesfor each of said rods, said plates being carriedby said base and located longitudinally of a rod and with platesindividually adjustable relative thereto; and electrical means totranslate mechanical vibrations of said rod to electrical vibrationsincluding said rod and collector plates in a capacitative relationship.

5. In an electric musical instrument, a plurality of fixed-free rods,each of said rods being tuned to a predetermined tone thereof and havingeven harmonic pattern producing means therefor including a groovedportion adjacent the fixed end thereof; a base; rod holders adjustablymounted on said base and having means adjacent the outer end thereof foradjustably gripping said rods substantially circumferentially at theirpoint of emergence from said holders; selectively operable strikers forsaid rods; translating means for changing mechanical vibrations of saidrods to electrical vibrations; and an electro-acoustical translatingmeans producing tones when said rods are struck having substantially thesame relationship between the fundamental tone of a rod and the harmonicpattern thereof for all of said rods.

6. In an electric musical instrument, a vibrator, a normally energizedstriker for said vibrator, an alternating current operated restrainingmeans for said striker, an electrical pick-up for said vibrator, andelectrical means connected relative to said restraining means andpick-up to substantially eliminate undesirable induced alternatingcurrent from said restraining means in the output of said pick-up.

7. In an electric musical instrument having a vibrator, a striker forsaid vibrator, alternating current operated releasable restraining meansfor normally holding said striker in an energized position, arestraining means support, an electrical pick-up for said vibrator, andmeans to'connect said support to an alternating current out of phasewith that of said restraining means alternating current to substantiallyeliminate undesirable alternating current in the output of said pick-up.

8. In an electric musical instrument a plurality of rods, selectivelyoperable strikers for said rods, alternating current electromagnets fornormally holding said strikers in an energized position; a support forsaid electromagnet; electric pick-up means for said rods; andelectro-acoustical means connected to said pick-ups; and a phaseshifting network connected in phase with said electromagnet alternatingcurrent and having an output 180 out of phase with said electromagnetalternating current and similar in magnitude thereto connected to saidsupport for substantially eliminating undesirable alternating currenthum in the output of said electrical pick-ups.

9. In an electric musical instrument, a plurality of rods, each of saidrods being tuned to a predetermined tone and having even harmonicpattern producing means therefor, selectively operable strikers for saidrods, alternating current magnet restraining means for said strikers,supports for said magnets, a multiplate collector having individuallyadjustable closely adjacent plates for each of said rods, an electriccircuit connected to said collectors and having attenuating means forone of the tones of each of said rods, means to introduce an alternatingcurrent out of phase with said magnet current into said support toprevent undesirable induced alternating current from said magnets insaid collectors, and a loudspeaker connected to said electric circuitproducing tones when said rods are struck having the same relationshipbetween the fundamental of a rod and the harmonic pattern thereof foreach of said rods.

10. In an electric musical instrument, a plurality of fixed-free rods,each of said rods being tuned to a predetermined tone and each rodhaving means thereon to produce an even harmonic pattern, selectivelyoperable strikers for said rods, translating means for changingmechanical vibrations of said rods to electrical vibrations, an electriccircuit including attenuating means attenuating predetermined tones ofsaid rods, a bass attenuating means connected to the instrument foradditionally attenuating the bass to a total minimum of about 23-30decibels, and an electro-acoustic means translating said electricvibrations into tones when said rods are struck having substantially thesame relationship between the fundamental tone of a rod and the harmonicpattern thereof for all of said rods.

JACOB T. KUNZ.

REFERENCES CITED The following references are of record in the fiie ofthis patent:

UNITED STATES PATENTS Number Name Date 1,269,511 Roberge June 11, 19181,935,215 Severy Nov. 14, 1933 1,994,560 Brewer et al Mar. 19, 19352,187,251 Severy Jan. 16, 1940 2,223,206 Dome Nov. 26', 1940 2,273,333Schluter Feb. 17, 1942 2,286,587 Sundt June 16, 1942 2,330,261 BeyerSept. 28, 1943 2,321,366 Demuth June 8, 1943 2,352,438 Hruby June 27,1944 2,413,062 Miessner Dec. 24, 1946 FOREIGN PATENTS Number CountryDate 44,708 Norway Jan. 2, 1928 Certificate of Correction Patent No.2,472,595. June 7, 1949.

JACOB T. KUNZ It is hereby certified that error appears in the printedspecification of the above numbered patent requiring correction asfollows:

Column 5, line 48, for reeds read 7018;

and that the said Letters Patent should be read with this correctiontherein that the same may conform to the record of the case in thePatent Office.

Signed and sealed this 1st day of November, A. D. 1949.

THOMAS F. MURPHY,

Assistant G'ommz'ss'ioner 0 f Patents.

Certificate of Correction Patent No. 2,472,595. June 7, 1949.

JACOB T. KUNZ It is hereby certified that error appears in the printedspecification of the above numbered patent requiring correction asfollows:

Column 5, line 48, for reeds read TOCZS;

and that the said Letters Patent should be read With this correctiontherein that the same may conform to the record of the case in thePatent Ofiice.

Signed and sealed this 1st day of November, A. D. 1949.

THOMAS F. MURPHY,

Assistant C'ommissioner of Patents.

